1. Field of the Invention
The present invention relates to solar energy collector and storage modules and, more particularly, to modular collector and storage elements built of low-cost construction materials such that they can be used also for structural functions.
2. Summary of the Invention
The large scale utilization of solar energy can be enhanced significantly if the installed costs of solar systems can be reduced. A major step in this direction would be the replacement of relatively high-cost materials, such as copper or aluminum, used in solar collector systems with low-cost materials such as concrete or composites. A further step would be the development of solar collector concepts that are multi-functional.
The present invention addresses both of these steps by using low-cost construction materials such as concrete to fabricate modular solar energy collector system elements having the requisite strength and configuration to be integrated as structural parts of buildings and other constructions.
Concrete solar collectors of this invention have a potential efficiency substantially equal to conventional glass and metal collectors. Concrete is a relatively low-cost material and equipment is currently available for layups on a mass production basis. Construction and installation costs can be reduced because the material permits the elements to be molded to virtually any size and shape to fit the requirements and to meet contingencies of construction. Collectors built out of concrete can be patched easily if damaged and the material can be sealed to be impervious to potential corrosion. In addition, the construction material is readily available on almost a universal basis.
In this invention, the fluid passages in the collector and other elements of the system are molded integrally in the concrete body. In the fabrication process a dissolvable material formed into the labyrinthine configuration desired for the fluid passages is embedded in a matrix of concrete contained in a mold which will impart to the cast a desired size, shape, and finish. The dissolvable material is then dissolved by a suitable solvent to leave a pattern of voids that form fluid passageways in the concrete. The concrete is then allowed to cure both in the mold and after removal therefrom as required. After curing, the modular slabs and other shapes so produced can be used as wall elements of buildings, the floors or the aprons or patios around swimming pools and for any other structural function in which the capability of the elements to collect solar radiation, to store the collected energy, and to radiate it as required is of value. In an alternate embodiment of the solar collector of my invention, the body of the collector is cast concrete with a system of grooved fluid passageways therein and the side exposed to solar radiation is provided with a perforated metal energy absorber plate having spaced above it a transparent cover plate.